package it.gma.torero.operator;

import it.gma.torero.expression.AbstractBooleanExpression;
import it.gma.torero.operand.VariableBinder;

/**
 * In logic, a <a href="http://en.wikipedia.org/wiki/Tautology_(logic)">tautology</a> (from the Greek word ταυτολογία) is a formula which is
 * true in every possible interpretation. Philosopher Ludwig Wittgenstein first
 * applied the term to redundancies of propositional logic in 1921; it had been
 * used earlier to refer to rhetorical tautologies, and continues to be used in
 * that alternate sense. A formula is satisfiable if it is true under at least
 * one interpretation, and thus a tautology is a formula whose negation is
 * unsatisfiable. Unsatisfiable statements, both through negation and
 * affirmation, are known formally as contradictions. A formula that is neither
 * a tautology nor a contradiction is said to be logically contingent.
 * 
 * @author giordano
 * 
 */
public class Tautology extends AbstractBooleanExpression {

	public Tautology() {
		super();
	}
	
	public boolean evaluate() {
		return true;
	}

	@Override
	public String toString() {
		return Boolean.toString(true);
	}

	public boolean isConstant() {
		return true;
	}

	public void setContext(VariableBinder context) {
	
		
	}
}
